Vendor import of the Intel ACPI CA 20020815 drop.

1 files changed, 29 insertions, 5 deletions

diff --git a/sys/contrib/dev/acpica/hwacpi.c b/sys/contrib/dev/acpica/hwacpi.c
index 8391e55..9dffda3 100644
--- a/sys/contrib/dev/acpica/hwacpi.c
+++ b/sys/contrib/dev/acpica/hwacpi.c
@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
- *              $Revision: 58 $
+ *              $Revision: 60 $
  *
  *****************************************************************************/
 
@@ -190,13 +190,36 @@ AcpiHwSetMode (
 
     ACPI_FUNCTION_TRACE ("HwSetMode");
 
+    /*
+     * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
+     * system does not support mode transition.
+     */
+    if (!AcpiGbl_FADT->SmiCmd)
+    {
+        ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "No SMI_CMD in FADT, mode transition failed.\n")); 
+        return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
+    }
+
+    /*
+     * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
+     * in FADT: If it is zero, enabling or disabling is not supported.
+     * As old systems may have used zero for mode transition,
+     * we make sure both the numbers are zero to determine these
+     * transitions are not supported.
+     */
+    if (!AcpiGbl_FADT->AcpiEnable && !AcpiGbl_FADT->AcpiDisable)
+    {
+        ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "No mode transition supported in this system.\n"));
+        return_ACPI_STATUS (AE_OK);
+    }
+
     switch (Mode)
     {
     case ACPI_SYS_MODE_ACPI:
 
         /* BIOS should have disabled ALL fixed and GP events */
 
-        Status = AcpiOsWritePort (AcpiGbl_FADT->SmiCmd, 
+        Status = AcpiOsWritePort (AcpiGbl_FADT->SmiCmd,
                         (ACPI_INTEGER) AcpiGbl_FADT->AcpiEnable, 8);
         ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
         break;
@@ -207,7 +230,7 @@ AcpiHwSetMode (
          * BIOS should clear all fixed status bits and restore fixed event
          * enable bits to default
          */
-        Status = AcpiOsWritePort (AcpiGbl_FADT->SmiCmd, 
+        Status = AcpiOsWritePort (AcpiGbl_FADT->SmiCmd,
                     (ACPI_INTEGER) AcpiGbl_FADT->AcpiDisable, 8);
         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
                     "Attempting to enable Legacy (non-ACPI) mode\n"));
@@ -231,12 +254,13 @@ AcpiHwSetMode (
     {
         Status = AE_NO_HARDWARE_RESPONSE;
 
-        if (AcpiHwGetMode() == Mode) {
+        if (AcpiHwGetMode() == Mode)
+        {
             ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n", Mode));
             Status = AE_OK;
             break;
         }
-        AcpiOsStall(1000);  
+        AcpiOsStall(1000);
         Retry--;
     }